NBC News airing documentary on Valerie Harper

FILE - This May 16, 2012 file photo shows actress Valerie Harper at the Friars Club Roast of Betty White in New York. Harper has agreed to make a first-person account of her battle with terminal cancer for NBC News. The network said that Meredith Vieira will be host of the documentary, which will air in prime-time. No airdate was set. (AP Photo/Charles Sykes, File)

NEW YORK (AP) — Valerie Harper has agreed to give a first-person account of her battle with terminal cancer to NBC News.

The network says Meredith Vieira will host the documentary, which will air in prime time. No airdate has been set.

The actress gained fame playing Rhoda Morgenstern on television's "The Mary Tyler Moore Show" and "Rhoda." She announced this year that she has been diagnosed with brain cancer. She was given as little as three months to live when diagnosed March 6, which she has already exceeded.

NBC says the 73-year-old Harper has allowed cameras to follow her since she was diagnosed.